An efficient manufacturing process for xcex1-olefins using certain iron containing ethylene oligomerization catalysts, comprises one or more liquid full reactors which are approximately at the bubble point of reacting ethylene, and optionally a final reactor to which no ethylene is fed, both operating under other specified conditions.
xcex1-Olefins are important items of commerce, billions of kilograms being manufactured yearly. They are useful as monomers for (co)polymerizations and as chemical intermediates for the manufacture of many other materials, for example detergents and surfactants. Presently most xcex1-olefins are made by the catalyzed oligomerization of ethylene by various catalysts, especially certain nickel complexes or aluminum alkyls, see for instance U.S. Pat. No. 4,020,121 and I. Kroschwitz, et al., Ed., Kirk-Othmer Encyclopedia of Chemical Technology, 4th Ed., Vol. 17, John Wiley and Sons, New York, pp. 839-858. Depending on the catalyst used and the product distribution desired various processes are used, but they tend to operate at high pressures, and/or high temperatures, and/or have large recycle streams, and/or be complex (for example recycle of catalyst streams), all of which increases the capital cost of the manufacturing plant and/or increases plant operating costs, both of course undesirable. Therefore better processes for making xcex1-olefins are of commercial interest.
Recently, as reported in U.S. Pat. No. 5,955,555 and U.S. Pat. No. 6,103,946, both of which are hereby incorporated by reference herein for all purposes as if fully set forth, it has been found that iron complexes of certain tridentate ligands are excellent catalysts for the production of xcex1-olefins from ethylene. Described herein is a manufacturing process for xcex1-olefins which is especially useful with such catalysts. This process results in lower capital costs for the manufacturing plant and/or lower operating costs for the plant than is found in other processes.
This invention concerns a process for the production of a linear xcex1-olefin product, comprising the step of contacting, in a continuous stirred tank reactor or its equivalent, process ingredients comprising an active ethylene oligomerization catalyst composition, ethylene and a solvent, at a temperature of from about 35xc2x0 C. to about 80xc2x0 C., and at a pressure such that the continuous stirred tank reactor or its equivalent is essentially single phase liquid full, wherein the active ethylene oligomerization catalyst comprises an iron complex of a compound of the formula 
wherein:
R1, R2 and R3 are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl or an inert functional group, provided that any two of R1, R2 and R3 vicinal to one another taken together may form a ring;
R4 and R5 are each independently hydrogen, hydrocarbyl, substituted hydrocarbyl or an inert functional group;
R6 and R7 are each independently a substituted aryl having a first ring atom bound to the imino nitrogen, provided that:
in R6, a second ring atom adjacent to said first ring atom is bound to a halogen, a primary carbon group, a secondary carbon group or a tertiary carbon group; and further provided that
in R6, when said second ring atom is bound to a halogen or a primary carbon group, none, one or two of the other ring atoms in R6 and R7 adjacent to said first ring atom are bound to a halogen or a primary carbon group, with the remainder of the ring atoms adjacent to said first ring atom being bound to a hydrogen atom; or
in R6, when said second ring atom is bound to a secondary carbon group, none, one or two of the other ring atoms in R6 and R7 adjacent to said first ring atom are bound to a halogen, a primary carbon group or a secondary carbon group, with the remainder of the ring atoms adjacent to said first ring atom being bound to a hydrogen atom; or
in R6, when said second ring atom is bound to a tertiary carbon group, none or one of the other ring atoms in R6 and R7 adjacent to said first ring atom are bound to a tertiary carbon group, with the remainder of the ring atoms adjacent to said first ring atom being bound to a hydrogen atom.
These and other features and advantages of the present invention will be more readily understood by those of ordinary skill in the art from a reading of the following detailed description. It is to be appreciated that certain features of the invention which are, for clarity, described below in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination.